Self contained gas powered surgical apparatus

Abstract: A self-contained gas powered endoscopic surgical apparatus so is provided for placing lateral lines of surgical fasteners into body tissue. The apparatus includes a frame portion 52, an elongated portion 54 extending from the frame portion, and an articulating fastener applying assembly 58 associated with a distal end of the elongated portion. The fastener applying assembly includes a base portion, a staple cartridge housing, and an anvil member 56 which has a forming surface thereon against which surgical fasteners are driven as they are ejected from the cartridge housing. A self-contained pneumatic system 68 is associated with the frame portion and is actuable to eject the surgical fasteners from the cartridge assembly. A first mechanism is provided for effectuating the rotation of the fastener applying assembly about an axis defined by the body portion, a second mechanism 452 is provided for effectuating the articulation of the fastener applying assembly, and a third mechanism 562 is provided for independently rotating the cartridge housing and anvil member relative to a longitudinal axis defined by the base position to increase the range of operability of the apparatus.

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to surgical stapling apparatus, and more particularly to surgical apparatus which are powered by self contained relatively low pressure gas systems to perform sequential operations such as tissue clamping, staple forming and/or tissue cutting. 2. Description of Related Art Surgical stapling apparatus is known wherein tissue is first grasped or clamped between opposing jaw structure and then fastened by means of fasteners. In some instruments a knife is provided to cut tissue which has been joined. The fasteners are typically in the form of surgical staples. However, two part polymeric type fasteners are also known. Instruments for this purpose can comprise two elongated fingers which are respectively used to capture or clamp tissue. Typically, one of the fingers carries a disposable cartridge housing wherein a plurality of staples are arranged in at least two lateral rows while the other finger comprises an anvil for curling the staple legs into a hook-like configuration upon their being driven against the anvil. The stapling operation is effected by a pusher which travels longitudinally along the cartridge carrying finger, with the pusher acting upon the staples to place rows of staples in body tissue. A knife may be optionally positioned in such a manner so as to operate sequentially immediately behind the pusher, and laterally positioned between the staple rows to longitudinally cut and/or open the stapled tissue between the rows of staples. Such instruments are disclosed in Bobrov et al. (U.S. Patent No. 3,079,606) and Green (U.S. Patent No. 3,490,675). These instruments comprise apparatus for simultaneously making a longitudinal incision and applying a row of staples on both sides of the incision. A later development disclosed in Green (U.S. Patent No. 3,499,591) applies a double row of staples on each side of the incision. This is accomplished by a cartridge assembly wherein a cam member moves within a guide path between two sets of staggered staple carrying grooves. Staple drive members located within the grooves each have two staple pusher plates, and sloping surfaces disposed within the guide path so as to be contacted by the longitudinally moving cam and be driven along the groove to effect ejection of two staples. The cartridge assemblies typically come in a plurality of sizes, each varying in both length and number of staples contained therein. Depending on the procedure to be performed, the surgeon must select the appropriate cartridge assembly. No provision is currently available to adjust the firing means of the instrument itself so that a wide variety of staple driving sequences may be accomplished using a single staple cartridge assembly. The instruments described above were all designed to be used in surgical procedures wherein surgeons have direct manual access to the operation site. However, in endoscopic or laparoscopic procedures surgery is performed through a small incision or through narrow cannulae inserted through small entrance wounds in the skin. In order to address the specific needs of endoscopic and/or laparoscopic surgical procedures, an endoscopic surgical stapling apparatus such as that shown in Green et al. (U.S. Patent No. 5,040,715) has been developed. This apparatus is well suited for such procedures and incorporates a distal end having an anvil and staple cartridge assembly and a manually operated handle assembly interconnected by an endoscopic portion which permits the instrument to be inserted into a cannula and be remotely operated by the surgeon. The instruments discussed above all require some degree of manually applied force in order to clamp, fasten and/or cut tissue. This manual application can prove awkward or difficult depending upon the orientation of the instrument relative to the surgeon, the type of tissue being operated on or the ability of the surgeon to apply the necessary force. Furthermore, because of the difficulty and expense of cleaning and sterilizing surgical instruments between uses, there is increasing interest in and demand for instruments which are disposable after use in a single surgical procedure rather than permanent and reusable. Self contained gas powered surgical staplers are known, as shown, for example, in U.S. Patent Nos. 3,618,842; 3,643,851; 3,662,939; 3,717,294; 3,815,476; and 3,837,555. Typically, these staplers include a replaceable cylinder which supplies gas (e.g., carbon dioxide or nitrogen) at relatively high pressure (e.g., 800 p.s.i.g.) for powering the instrument. The high pressure gas used in these staplers requires that the staplers be of relatively heavy construction in order to accommodate the high pressure involved. Because of their construction, these instruments are relatively expensive to manufacture and therefore often intended to be relatively permanent and reusable. Use of a relatively low pressure gas is advantageous to enable a stapler to be made of lighter construction and less expensive materials. This is desirable to lower the cost and make the stapler economically disposable. The stapler must, however, be capable of generating the substantial forces required to form the staples. Typically, the staples are metal wire which is partially formed prior to use and which must be further formed (e.g., crimped against an anvil) by the stapler. To generate the relatively large forces required to form the staples with low pressure gas would ordinarily require a relatively large pneumatic actuator. This is undesirable because a large actuator makes the stapler bulky and difficult to work with. In addition, a large actuator unnecessarily consumes a large amount of gas during the portion of actuator motion when relatively large forces are not required, i.e., during the first part of the actuator stroke when the staple is merely being advanced to the staple forming position. The gas which is thus effectively wasted substantially reduces the number of stapling operations which can be performed by the stapler before its gas supply is exhausted. This substantially shortens the useful life of the stapler if the gas supply is not replaceable, and even if the gas supply is replaceable, it undesirably increases the frequency with which the gas supply must be replaced. Although it may be desirable to perform functions of the stapling apparatus automatically using the self-powering elements in the apparatus, it may also be desirable for the initial function to be at least partly manual. For example, if the initial function is tissue clamping, it may be preferable to initiate such function manually so that it can be performed slowly and precisely and the results inspected and corrected if necessary before the automatic self-powered portion of the operating sequence begins. See, for example, U.S. Patent Nos. 4,349,028 and 4,331,277 to Green. Many of the instruments described above are limited in their range of operability. Improvements have been made in the art of surgical instruments to increase their range of operability. For example Nierman (U.S. Patent No. 4,880,015) discloses a biopsy forceps designed for use through a flexible fiberoptic bronchoscope. The biopsy forceps includes a handle connected to a thin elongated flexible shaft with a distal portion thereof hinged to the shaft. A grasping tool or biopsy forceps is attached to the distal hinged portion. Control wires extend from the handle through the distal to the shaft for controlling the angular rotation of the distal portion of the instrument. An endoscopic surgical system is disclosed in EP-A-552050 which has the technical features recited in the pre-characterising part of claim 1, below. In accordance with these and other principles, it is an object of the present invention to provide a self contained gas powered surgical instrument for driving surgical fasteners into body tissue which instrument has an increased range of operability. The present invention is defined by claim 1 below. The present invention can provide a self contained gas powered surgical apparatus insertable through a small incision or narrow tube for driving surgical fasteners into body tissue and cutting the body tissue between rows of staples. The present invention can provide a self contained gas powered surgical apparatus which is disposable after use. Preferred embodiments of the present invention provide a self contained gas powered surgical apparatus having a mechanism which will prevent clamping of tissue unless the cartridge has been properly inserted in the instrument. Preferred embodiments of the present invention provide a self contained gas powered surgical apparatus having sealing structure for inhibiting the escape of insufflation gas through the apparatus. Preferred embodiments of the present invention provide a self contained gas powered surgical apparatus having counter structure for displaying the number of times the instrument has been fired. Preferred embodiments of the present invention provide a self contained gas powered surgical apparatus with structure to disable the apparatus after a predetermined number of firings have occurred. Preferred embodiments of the present invention provide a surgical apparatus that provides a full range of remotely actuated movements to the distal working members of the apparatus to facilitate interaction with and manipulation of tissue. Preferred embodiments of the present invention provide a self contained gas powered surgical apparatus having a pistol-type handle assembly. Preferred embodiments of the present invention provide a self contained gas powered apparatus having a pneumatic actuation system including a movable valve member configured to interact with a stationary gas supply canister. SUMMARY OF THE INVENTION The invention can be realised in the form of a self contained endoscopic surgical instrument which is at least partially operable by means of a relatively low pressure pneumatic assembly. The surgical instrument in accordance with one embodiment of the present invention is a surgical stapling apparatus which is adapted for placing one or more longitudinal rows of staples. This apparatus may further include a knife for making an incision in body tissue between the rows of staples. The latter configuration may find particular use in adjoining two hollow organs or in removing an organ, such as the appendix, the gallbladder, etc. Normally, the elongate body portion is tubular.In a preferred embodiment of the subject invention a cable loop assembly is associated with the elongate body portion of the instrument for effectuating the articulation of the cartridge housing base portion relative to the elongate body portion. The cable loop assembly includes a cable member, a pivot block member mounted for rotation in a distal end portion on the tubular body portion about an axis perpendicular to the longitudinal axis thereof, and a rotation control member operatively associated with the tubular body portion of the apparatus for manipulating the cable loop assembly. A cartridge element, which includes a plurality of surgical staples slidably mounted therein, and having a tissue engaging surface, is receivable within the cartridge housing portion of the cartridge assembly. An anvil member is also provided which has a staple forming surface formed thereon and which is mounted adjacent the cartridge housing portion of the cartridge assembly such that the anvil member is movable between an open position and a closed position wherein the staple forming surface is in close cooperative alignment with the tissue engaging surface of the cartridge element. The apparatus further comprises means associated with the elongate body portion for moving the anvil member between the open and the closed positions, and means for ejecting the surgical staples from the cartridge element in such a manner so as to cause the staples to engage and form on the staple forming surface of the anvil member. The means for moving the anvil member may comprise a linkage mechanism associated with the frame portion and extending into the tubular body portion to a cable mechanism. The cable mechanism includes a cable member mounted at a leading end thereof to the linkage mechanism and at a trailing end thereof to the cartridge housing portion of the cartridge assembly. The anvil member is operatively associated with the cable member intermediate the ends thereof. The means for ejecting the surgical fasteners may comprise a plurality of pusher elements in abutment with the surgical fasteners, and at least one cam bar for actuating the pusher elements. The cam bar can be mounted in an adapter which translates within the cartridge assembly. In one embodiment of the cartridge assembly, the cam bar is fixedly mounted in the adapter while in another embodiment the cam bar is freely movable within the adapter. The articulating cartridge assembly of the subject invention may also be provided with bearing means for guiding the translation of the cam bars as they traverse the cartridge assembly at such times when the cartridge housing portion of the cartridge assembly is articulated relative to the cartridge mounting portion thereof. The surgical apparatus of the subject invention normally includes a self contained pneumatic system which is disposed in the frame portion of the instrument and which includes a supply canister of relatively low pressure gas and a valve member. The system is operatively connected to a pneumatic actuator mechanism which actuates the means for ejecting the surgical fasteners from the cartridge element. To expel gas from the canister, the system may be configured to accommodate either the movement of the canister relative to a fixed valve member or, the movement of the valve member relative to a fixed canister. In another preferred embodiment of the surgical apparatus of the subject invention, the instrument includes a fastener applying assembly having an articulated base portion and fastener applying means which include a cartridge housing configured to retain a replaceable fastener cartridge and an anvil member against which fasteners are driven when ejected from the cartridge. Means are provided for effectuating the articulation of the fastener applying assembly between a first position generally in alignment with the longitudinal axis of the elongated body of the instrument and a second position angularly disposed with respect to the longitudinal axis of the elongated body. Means are provided for effectuating rotation of the fastener applying assembly about the longitudinal axis defined by the elongated body relative to the frame portion. Means are also provided for effectuating the independent rotation of the fastener applying means relative to the base portion of the fastener applying assembly to further increase the range of operability of the surgical apparatus of the subject invention. In a preferred embodiment of the subject invention, the fastener ejection means includes a camming sled which is movable through the staple cartridge from a distal end portion thereof toward a proximal end portion thereof. The camming sled is configured to interengage with the pneumatic actuator mechanism of the subject invention to effect the sequential ejection of fasteners from the cartridge. In a preferred embodiment of the surgical apparatus of the subject invention, a counter mechanism is provided for indicating to a user the number of times the instrument has been operated or, alternatively, the number of remaining firings available. The counter mechanism is preferably operatively associated with the pneumatic actuation assembly and is configured to advantageously disable the pneumatic actuation system after the instrument has been operated a predetermined number of times. This prevents the apparatus from being operated beyond the capacity of the gas supply. The surgical apparatus of the subject invention may further comprise sealing means associated with the tubular body portion of the instrument for prohibiting the egress of insufflation gas therethrough during surgical procedures. The instrument may be constructed either as a reusable unit or as a single use, disposable unit or, alternatively may be formed with a reusable handle portion and replaceable body portions and/or staple carrying cartridges. The handle portion of the surgical instrument may have a palm grip configuration or a pistol grip configuration depending upon the needs of the surgeon. The present invention advantageously permits surgeons to perform internal surgical procedures including stapling and/or cutting simply by manually clamping the tissue to be manipulated and pneumatically actuating the fastener applying means. This results in greater convenience and ease of use of the instrument as well as more uniform actuation of the instrument mechanisms. Further features of the invention, its nature, and various advantages will become more apparent from the accompanying drawings and the following detailed description of the invention. BRIEF DESCRIPTION OF THE DRAWINGS Preferred embodiments of the invention are described hereinbelow with reference to the drawings wherein: Figs. 1 to 64 are cancelled; Fig. 65 is a perspective view of a self-contained gas powered articulable surgical apparatus constructed in accordance with a preferred embodiment of the subject invention; Fig. 66 is an exploded perspective view of the fastener applying assembly of the gas powered surgical apparatus illustrated in Fig. 65; Fig. 66a is a perspective view of another embodiment of the drive mechanism which defines a portion of the fastener applying assembly illustrated in Fig. 66; Fig. 67 is an enlarged perspective view of the cam sled which defines a portion of the fastener applying assembly illustrated in Fig. 66; Fig. 68 is a cross-sectional view taken along line 68-68 of Fig. 67; Fig. 69 is an enlarged perspective view of a rotary cam which defines a portion of the fastener applying assembly illustrated in Fig. 66; Fig. 70 is a side elevational view of the rotary cam illustrated in Fig. 69; Fig. 71 is a side elevational view in cross-section of the fastener applying assembly of the gas powered surgical apparatus illustrated in Fig. 65 with the cartridge assembly thereof disposed in an open position; Figs. 71a and 71b are side elevational views in cross section of the fastener applying assembly in the open and closed positions, respectively. Fig. 72 is a side elevational view in cross-section of the fastener applying assembly of the surgical apparatus illustrated in Fig. 65 with the cartridge assembly thereof disposed in a closed position; Fig. 73 is a side elevational view in cross-section of the fastener applying assembly illustrated in Fig. 72 with the cam sled of Fig. 67 moved toward the proximal end portion of the cartridge as the apparatus is actuated; Fig. 74 is a side elevational view in cross-section of the fastener applying assembly illustrated in Fig. 72 with the cam sled of Fig. 67 disposed adjacent the proximal end portion of the cartridge after the apparatus has been actuated; Fig. 75 is a side elevational view in cross-section of the frame portion of the surgical apparatus illustrated in Fig. 65 with the piston in a prefired position within the compression chamber before the surgical apparatus is actuated; Fig. 76 is a side elevational view in cross-section of the frame portion of the surgical apparatus illustrated in Fig. 65 with the piston moved partially through the compression chamber; Fig. 77 is a side elevational view in cross-section of the frame portion of the apparatus illustrated in Fig. 76 with the piston advanced through the compression chamber to disengage the firing control mechanism and index the counter assembly of the subject invention; Figs. 78-80 are perspective, elevational, and cross-sectional views, respectively, of the latching link which defines a portion of the firing control linkage illustrated in Fig. 75; Figs. 81-84 are perspective and elevational views, respectively, of the rocker link which defines a portion of the firing control linkage illustrated in Fig. 75; Fig. 85 is an elevational view in cross-section of the proximal end of the frame portion of the gas powered surgical apparatus of Fig. 65 illustrating the firing control linkage; Figs. 86a and 86b are side elevational views in cross-section of another approximation shaft constructed in accordance with a preferred embodiment of the subject invention which includes a tensioning screw; Fig. 87 is a side elevational view in cross-section of the body of the surgical apparatus of Fig. 65 illustrating the articulation control mechanism and the control mechanism for effecting the independent rotation of the fastener applying assembly and depicting the fastener applying assembly disposed in an articulated and rotated position; Fig. 87a is an enlarged plan view in cross-section of the transition area between the body and the fastener applying assembly illustrating a rotation transmission mechanism; Fig. 88 is a cross-sectional view taken along line 88-88 of Fig. 65 illustrating the articulation control mechanism shown in Fig. 87; Fig. 89 is a cross-sectional view taken along line 89-89 of Fig. 65 illustrating the rotation control mechanism shown in Fig. 87; Fig. 90 is another self-contained gas powered surgical apparatus constructed in accordance with a preferred embodiment of the subject invention which includes a pistol-type handle assembly; Fig. 90a is a perspective view of the fastener applying assembly of the surgical apparatus illustrated in Fig. 90 disposed in an articulated position with the fastener applying assembly independently rotated in a clockwise direction relative to the elongated body; Fig. 91 is a side elevational view in partial cross-section of the handle assembly of the surgical apparatus illustrated in Fig. 90 with the approximation handle thereof disposed in a neutral position prior to operation of the apparatus; Fig. 92 is an enlarged perspective view of the safety mechanism which is associated with the pneumatic actuation system of the surgical apparatus illustrated in Fig. 90; Fig. 93 is an enlarged perspective view of the safety mechanism illustrated in Fig. 92 disposed in an unlocked position to permit user access to the actuation trigger; Fig. 94 is a side elevational view in partial cross-section of the handle assembly illustrated in Fig. 91 with the approximation handle thereof disposed in a compressed position and the pneumatic actuation system thereof actuated to drive the piston through the compression chamber; Fig. 95 is a side elevational view in partial cross-section of a portion of the handle assembly illustrated in Fig. 91 with the piston disposed adjacent the proximal end of the compression chamber to disengage the firing control linkage; Fig. 95a is a localized elevational view in partial cross-section of the counter mechanism of the gas powered surgical apparatus of the subject invention; Fig. 96 is a cross-sectional view taken along line 96-96 of Fig. 91 illustrating the articulation control mechanism of the gas powered surgical apparatus of Fig. 90; and Fig. 97 is a cross-sectional view taken along line 97-97 of Fig. 91 illustrating the control mechanism for effecting the independent rotation of the fastener applying assembly of the gas powered surgical apparatus shown in Fig. 90. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS For a description of what is shown in cancelled Figures 1 to 64, the reader is referred to Applicant's EP-A-603472 which has an earlier date than the present application, and has to be considered as part of the state of the art under EPC Article 54(3). It is generally accepted that endoscopic procedures are more common than laparoscopic procedures. Accordingly, the present invention shall be discussed in terms of endoscopic procedures and apparatus. However, use herein of terms such as "endoscopic", "endoscopically" and "endoscopic portion", among others, should not be construed to limit the present invention to a stapling and cutting apparatus for use only in conjunction with an endoscopic tube. On the contrary, it is believed that the present invention may find use in any procedure where access is limited to a small incision, including but not limited to laparoscopic procedures. Also, as used herein the terms "fasteners" and "staples" shall be treated equivalently. Unless otherwise stated, the term "cartridge assembly" shall include at least the cartridge itself and staples or fasteners and staple drive members disposed therein. In the drawings and the description which follows, as is customary, the term "proximal" refers to the end which is closest to the operator while the term "distal" will refer to the end which is furthest from the operator. Referring to Fig. 65, a gas powered surgical apparatus constructed in accordance with a preferred embodiment of the subject invention is illustrated and is designated generally by reference numeral 810. Surgical apparatus 810, like the surgical apparatus 700 described hereinabove, is configured to provide the surgeon with an increased range of operability during the performance of an endoscopic or laparoscopic surgical procedure. In brief, surgical apparatus 810 comprises a frame 812 which houses a pneumatic actuation assembly 814 (see generally, Fig. 75), an elongated body 816 which extends from the frame 812 and which defines a longitudinal axis, and a fastener applying assembly 818 which is pivotally associated with a distal end of the elongated body 816. The surgical apparatus 810 includes three movement control mechanisms for effectuating distinct movements of the fastener applying assembly 818. These mechanisms include a rotation control collar 820 for controlling rotation of the fastener applying assembly 818 about the longitudinal axis defined by the elongated body 816 relative to frame 812 (i.e., rotation about the x-axis), an articulation control wheel 822 for controlling pivotal movement of the fastener applying assembly 818 relative to the distal end of the elongated body 816 (i.e., rotation about the y-axis), and a control wheel 824 for effecting the independent rotation of the fastener applying assembly 818 about a longitudinal axis extending therethrough (i.e., rotation about the z-axis). Each of these movement controlling mechanisms will be described in greater detail hereinbelow. Referring now to Fig. 66, the fastener applying assembly 818 of surgical apparatus 810 includes a cartridge housing 826 configured to receive a replaceable cartridge 828 which contains a plurality of surgical fasteners 825 and a plurality of corresponding staple pushers 827. The fastener applying assembly 818 further includes an anvil 830 against which the surgical fasteners 825 are driven when they are ejected from cartridge 828. The replaceable cartridge 828 includes a pair of outwardly extending engaging U-shaped ears 828a and 828b which interact with corresponding apertures 829 formed in the side walls of the cartridge housing 826 to releasably secure the cartridge 828 within the cartridge housing 826. Cartridge also includes a proximal triangular extension 831 that is adapted to slide within slots 833 formed in cartridge housing 826. When loading cartridge 828 into cartridge housing 826, cartridge 828 may be angularly oriented with respect to cartridge housing 826, e.g., at a 30 to 45 degree angle, with extension 831 positioned within slots 833, and then cartridge 828 may be rotated down such that U-shaped ears 828a, 828b engage apertures 829, thereby firmly seating cartridge 828 in cartridge housing 826. Anvil 830 includes a staple forming portion 832 and an anvil mounting portion 834. The mounting portion 834 includes a rearwardly extending annular flange 836 which is dimensioned and configured for rotational engagement within a correspondingly dimensioned and configured annular groove 838 which is defined in the articulated knuckle 840 of surgical apparatus 810 (see generally, Fig. 71). The flange and groove connection which is maintained between the anvil 830 and the knuckle 840 may be further facilitated by the provision of a plurality of radially spaced apart guide pins which extend into the annular groove 838 from the flange 836, or by providing a race of ball bearings which would be disposed within the annular groove 838 to reduce friction as the annular flange rotates within the groove 838. Referring to Figs. 65, 66 and 72, the articulated knuckle 840 is pivotally mounted upon a main pivot pin 841 which is maintained within a yoke 842 provided at the distal end of the elongated body 816. Yoke 842 facilitates pivotal movement of the fastener applying assembly 818 in response to the operation of the articulation control wheel 822. With continued reference to Figs. 66 and 71, engaging stems such as stem 844 are formed within the mounting portion 834 of anvil 830 for facilitating the engagement of the cartridge housing 826 and the anvil 830 (see, for example, Fig. 71). More particularly, the proximal ends of the side walls 846 and 848 of cartridge housing 826 are provided with notches 846a and 848a, respectively, for engaging the stem 844. Once engaged, the stems enable relative pivotal movement of the cartridge housing 826 and the anvil 830. Referring to Figs. 66 and 69-71, the cartridge housing 826 and the anvil 830 are operatively interconnected by a unique rotary cam member 850 which is configured to effect the relative movement of the cartridge housing 826 and the anvil 830 during a surgical procedure More particularly, the rotary cam member 850, which is illustrated specifically in Figs. 69 and 70, is pivotably mounted to anvil member 830 by a pin 852 (Fig. 66) which extends through aperture 854 in rotary cam 850. A cam pin 856, extending through a circuitous cam slot 858, mounts the cartridge housing 826 to the rotary cam 850 through apertures 846b and 848b, thereby operatively interconnecting the anvil 830 and the cartridge housing 826. Referring to Figs. 71 and 72, to effect the relative movement of the anvil 830 and the cartridge housing 826, an actuation cable 860 is connected to rotary cam 850 by a yoke 862 through apertures 857a and 857b. Actuation cable 860 extends through the elongated body 816 of surgical apparatus 810 and is connected to an approximation shaft 866, the movement of which is controlled by approximation handle 868 which is pivotably associated with frame 812 (see generally Figs. 75 and 76). In use, closure of the approximation handle 868 toward frame 812 will cause proximal movement of the approximation shaft 866 and actuation cable 860. As a result, the rotary cam 850 will be drawn in a generally proximal direction, effectuating the counter-clockwise rotation of the rotary cam 850 about pivot pin 852. Consequently, the cam pin 856 will translate relative to cam slot 858, from the position illustrated in Fig. 71 to that illustrated in Fig. 72, thereby causing the approximation of the cartridge housing 826 and the anvil 830. To return the cartridge housing 826 to an open position, approximation handle 868 is pivoted away from frame 812 to the position shown in Fig. 75, thereby urging the approximation shaft 866 in a distal direction. As a result, the tension exerted on actuation cable 860 is relieved, and a coiled spring 870 which is disposed proximal to yoke 862, urges the yoke 862 in a generally distal direction, causing the rotary cam 850 to pivot in a clockwise direction about pin 852. Consequently, cam pin 856 will return to the position illustrated in Fig. 71, and the fastener applying assembly 818 will be in an open position. If desired and as shown in Figs. 71a and 71b, one or more spring members, e.g., coil spring 855, may be anchored within anvil mounting portion 834 to bias the fastener applying assembly 818 into the open position. The coil spring 855 engages a spring plate 857 on fastener applying assembly 818 and is compressed, as shown in Fig. 71b, when anvil 830 and cartridge housing 826 are approximated. When in the open position, coil spring 855 assumes a non-compressed configuration, as shown in Fig. 71a. Referring to Figs. 86a and 86b, an alternative embodiment of an approximation shaft for effecting the longitudinal movement of actuation cable 860 in response to pivotal movement of approximation handle 868 is illustrated and is designated generally by reference numeral 872. Approximation shaft 872 is slidably associated with frame 812 and includes a distal mounting portion 874 for engaging a coupling 876 to which actuation cable 860 is mounted. An adjustment screw 878 for adjusting the tension imparted upon actuation cable 860 is disposed in the proximal portion 880 of approximation shaft 872. The adjustment screw 878 is formed with a transverse mounting pin 882 for connecting the screw 878 to the handle link 884 which interconnects the approximation handle 868 and the frame 812. In use, movement of the handle 868 toward and away from the frame 812 will cause corresponding proximal and distal movement of approximation shaft 872. Referring again to Fig. 66, the fastener applying assembly 818 includes a unique fastener ejection mechanism for sequentially ejecting a plurality of surgical fasteners 825 from the cartridge 828 during a surgical procedure. The fastener ejection mechanism includes a cam sled 890, illustrated specifically in Figs. 67 and 68, which comprises a base 892, and a plurality of upstanding cam plates 894a-894d. The base 892 of cam sled 890 includes a notched area 898 for releasably retaining the flanged engaging end 900 of a draw bar 902. An elongated track 904 is formed in the floor 845 of cartridge housing 826 for guiding the translation of draw bar 902 as it is drawn from a distal position to a proximal position when the pneumatic actuation system 814 is operated during a surgical procedure. The upstanding cam plates 894a-894d of cam sled 890 are configured to sequentially actuate pushers 827 which are disposed within cartridge 828 for urging the fasteners 825 therefrom. [The cam plates may be disposed in a staggered configuration to balance forces within the cartridge as the fasteners are sequentially ejected therefrom.] The cam plates 894a-894b translate within corresponding longitudinal slots (see generally, Fig. 18) which are formed in the cartridge 828 and communicate with the pushers 827. An engaging arm 896 depends from the base 892 of cam sled 890 between cam plates 894b and 894c. This arm 896 engages a knife member 906 as the cam sled 890 translates from the distal end of cartridge 828 to the proximal end thereof for forming an incision in tissue as fasteners 825 are applied thereto. As best seen in Fig. 71, the knife member 906 is positioned on a shank 908 mounted by a frangible shear pin 910 adjacent the distal end of cartridge 828. Initially, as illustrated in Fig. 72, the shank 908 is pivoted into a recessed position to facilitate the engagement thereof by engaging arm 896 as the cam sled 890 translates proximally. Referring to Figs. 72-74, in operation, the cam sled 890 is drawn proximally by the draw bar 902 under the influence of the pneumatic actuation assembly 814. A downwardly extension hook portion 908a of shank 908 is subsequently engaged by arm 896 as shown in Fig. 73. Concomitantly, the driving forces produced by the pneumatic actuation assembly 814 effectively operate to break shear pin 910 and release the knife member 906, whereupon the camming sled 890 and the knife member 906 translate as an integral unit to the proximal end portion of cartridge 828, as illustrated in Fig. 74. After the fasteners 825 have been driven from cartridge 828, the entire cartridge, along with the cam sled 890 and the knife member 906 may be removed from the cartridge housing 826 and replaced with a new, loaded cartridge. The new cartridge will contain a distally positioned cam sled and frangibly mounted knife member. When the draw bar 902 is returned to its initial distal-most position and a cartridge is placed in the cartridge housing 826, the engaging end 900 of draw bar 902 reacquires the notched area 898 provided in the base 892 of cam slide 890 and the apparatus 810 is once again prepared for operation. In an alternative embodiment of the subject invention which is illustrated in Fig. 66a, the cam sled 890 is releasably engaged by a flanged fixture 905 which is mounted at the distal end of a drive cable 907. Drive cable 907 extends through the elongated body 816 of surgical apparatus 810 to the frame 812 where it operatively interconnects with the pneumatic actuation assembly 814. A reinforcing tube 909 is placed around drive cable 907 to impart rigidity thereto, particularly for the return stroke of drive cable 907 through cartridge housing 826. Reinforcing tube 907 is preferably fabricated from a pseudoelastic material, e.g., a nickel-titanium alloy such as Tinel, which is available from Raychem, Inc., Menlo Park, CA. Referring to Figs. 75-77, there is illustrated the pneumatic actuation assembly 814 which is disposed within the frame 812 of surgical apparatus 810 for effectuating the sequential ejection of a plurality of surgical fasteners 825 from cartridge 828. Pneumatic actuation assembly 814 differs from the pneumatic actuation systems which are provided in the previously described embodiments of the subject invention in that the valve 912 is configured to move relative to a stationary gas supply container 914 to cause gas to be released therefrom. Referring to Figs. 75-85, a unique firing control mechanism 915 is provided for effecting the controlled movement of valve 912 with respect to gas supply container 914. In brief, the firing control mechanism 915 includes a trigger 916, a rocker link 918, and a latching link 920. Trigger 916 includes a firing block 922 which is positioned to interact with rocker link 918 when the trigger 916 is depressed by the user. Rocker link 918, which is specifically illustrated in Figs. 81-84, is mounted upon a transverse shaft 924 and is biased into a prefired position by a coiled biasing spring 926 (see, Fig. 85). Biasing spring 926 serves to bias rocker link 918 against rotational movement as well as lateral movement with respect to transverse shaft 924. Rocker link 918 is defined by a central body portion 918a, a thrust portion 918b, and a pusher portion 918c which is configured to be urged against the valve 912 to move the valve toward the gas supply container 914 during actuation of the instrument. The body portion 918a of rocker link 918 defines an angled camming surface 918d for interacting with the latching link 920. Latching link 920, specifically illustrated in Figs. 78-80, is mounted upon a transverse shaft 928 and is biased into a prefired position by a coiled torsion spring 930 (Fig. 85). Latching link 920 includes a central body portion 920a, a camming arm 920b, a latch release plate 920c, and a latch arm 920d. The camming arm 920b is provided with an arcuate notch 920e for interacting with the camming surface 918d of rocker link 918. The latch arm 920d is formed with a tooth 920f for engaging a corresponding notch 918f which is formed in the central body portion 918a of rocker link 918. Referring to Fig. 76, depression of trigger 916 will urge firing block 922 against the thrust portion 918b of rocker link 918. As a result, rocker link 918 will rotate about transverse shaft 924 in a clockwise direction, against the bias of coiled spring 926 (Fig. 85), and concomitantly, the notch 918f will rotate on camming arm 920b and latch link 920 will pivot in a counter-clockwise direction. As rocker link 918 and latch link 920 continue to rotate in opposed directions, the tooth 920f on latch arm 920d will engage the notch 918f in rocker link 918. Thereupon, the pusher portion 918c of rocker link 918 will be urged against valve 912, pushing the valve 912 toward the gas supply container 914 to expel gas therefrom. Valve 912 will remain urged against gas supply container even if the depressive force is removed from trigger 916. When gas is expelled from supply container 914, it is transferred through valve 912, and flexible conduit 933, into a distal end of compression chamber 932 wherein a piston 934 is disposed. An elastomeric o-ring 939 is provided to seal piston 934 with respect to compression chamber 932. Preferably, the compression chamber 932 and the piston 934 are designed in a manner to maximize the cross sectional dimensions thereof, based on the available space therefor. For example, compression chamber 932 and piston 934 may each have an elliptical cross-sectional configuration to maximize their respective cross sectional dimensions with respect to a given frame geometry (see Fig. 85). As illustrated in Figs. 76-77, piston 934 will translate through the compression chamber 932 in a proximal direction as compressed gas is transferred into the chamber 932 from supply container 914. A drive shaft 936 depends distally from the piston 934 and is operatively connected to a coupling shaft (not shown) which extends through the elongated body 816 to connect with the draw bar 902. A stroke shaft 938 extends proximally from piston 934 and includes a transverse drive shaft extension 940 which is positioned and dimensioned to interact with the latch release plate 920c of latching link 920 when the piston 934 completes its firing stroke and translates to the proximal end of compression chamber 932. As best seen in Fig. 77, when the piston 934 reaches its proximal-most position within the compression chamber 932, the drive shaft extension 940 will contact the latch release plate 920c, causing the latching link 920 to pivot clockwise, thereby releasing tooth 920f from notch 918f. As a result, rocker link 918 will pivot in a counter-clockwise direction to permit valve 912 to return to a prefired position under the bias of coil spring 942. In addition, rocker link 918 will move transversely to disengage from the trigger 916, thereby allowing the mechanism to return to its initial position, even if the trigger 916 remains depressed. A coiled return spring 935 is disposed within chamber 932 and is associated with the piston 934 for returning the piston 934 to a distal position at the completion of its firing stroke. Referring to Figs. 75 and 77, surgical apparatus 810 includes a unique counter mechanism 945 which is operatively associated with the firing control mechanism 915 described hereinabove. The counter mechanism 945 is configured to visually indicate to the user the number of times the surgical apparatus 810 may be fired and to prevent the operation of the pneumatic actuation assembly 814 after a predetermined number of firing. This effectively prevents the apparatus 810 from being fired when there may be an insufficient quantity of compressed gas contained within gas supply canister 914. The counter mechanism 945 of the subject invention includes an elongated counter shaft 944 defining a main shaft portion 944a and a downturned proximal portion 944b. As best seen in Fig. 85, the main shaft portion 944a is maintained in a track 947 formed in the side wall of frame 812 and the proximal portion 944b is connected to the camming arm 920b of latching link 920. A ratchet tooth 944c depends from the main shaft portion 944a of counter shaft 944 which is configured to operatively interact with a linear rack member 946. Rack member 946 includes three ramped engagement notches 946a-946c and a fourth squared engagement notch 946d. A leaf spring 948 interacts with rack member 946 for sequentially maintaining the rack member 946 in an incremental indexed position. Numerical indicia are imprinted on the outside surface of rack member 946 and are sequentially visible through a windowed porthole 949 provided in the side wall of frame 812 (see, Fig. 65). Each numeral identifies the number of times the pneumatic actuation assembly 814 may be actuated to operate surgical apparatus 810. One skilled in the art will readily appreciate that, depending upon the volume of gas needed for actuation, and/or the volume of the supply container, the number of engagement notches formed on rack member 946 can be increased or decreased. As illustrated in Fig. 75, initially the rachet tooth 944c is disposed in the first ramped engagement notch 946a of rack member 946 (at such a time the numeral "4" will appear in the windowed porthole 949). When the apparatus 810 is operated for the first time, and the firing control mechanism 915 is activated, the counter shaft 944 will be drawn in a proximal direction as the latching link 920 is pivoted in a counter-clockwise direction. As a result, ratchet tooth 944c will move up the ramp of engagement notch 948a and into the second engagement notch 948b, as shown in Fig. 77. When the latching link 920 returns to a prefired position, the counter shaft 944 translates distally, causing the rack member 946 to translate therewith in a distal direction. Consequently, the next numeral will be moved into view of the windowed porthole 949, which, after the first firing, will be the numeral "3", indicating that surgical apparatus 810 may be operated three more times. When the surgical apparatus 810 is to be operated for the fourth and final time, ratchet tooth 944c will be positioned in the squared engagement notch 948d of rack member 946. When the counter shaft 944 and rack member 946 move distally, they are locked forward by leaf spring 948 as is latching link 920. As a result, after the fourth operation, the latching link 920 will be inhibited from pivoting into its prefired position under the influence of counter shaft 944 and will stay in the fired position. While maintained in the fired position, the latching link 920 will move the rocker link 918 transversely so as to be able to return to its prefired position. Consequently, when the trigger 916 is subsequently depressed, in an attempt to operate the instrument, the camming surface 918d on rocker link 918 will be unable to interact with the camming arm 920b to effect lateral movement of rocker link 918. Thus, the rocker link 918 will be unable to rotate and, as a result, the surgical apparatus 810 will be rendered inoperative. Referring again to Figs. 75 and 76, surgical apparatus 810 further includes a trigger blocking member 950 which is configured to prevent the depression of trigger 916 until such time as the approximation handle 868 is moved into a closed position (see Fig.76). The trigger blocking member 950 is biased into a blocking position by a coiled spring 952 and is moved out of the blocking position by a detent 954 which depends from handle 868 adjacent the proximal end thereof. The detent 954 is dimensioned and configured to extend through an aperture 955 formed in frame 812 when the approximation handle 868 is moved to a closed position (Fig. 76). Turning now to Figs. 87-89 in conjunction with Fig. 65, the movement control mechanisms of the subject invention which are discussed briefly hereinabove are illustrated. The first control mechanism activated by collar 820 is configured to effect axial rotation of the fastener applying assembly 818 about the longitudinal axis defined by the elongated body 816 of surgical apparatus 810 (i.e., about the x-axis). Collar 820 includes a frusto-conical portion 960 which is connected directly to the body 816 such that rotation of the collar 820 effects corresponding axial rotation of the entire body 816 and, consequently, effects axial rotation of the fastener applying assembly 818. The second mechanism activated by wheel 822 for controlling the articulated movements of the fastener applying assembly 818 (i.e., about the y-axis) is shown in Figs. 87 and 88, and includes a pinion gear assembly 964 defined by an outer ring gear 964a and an internal pinion gear 964b. The internal pinion gear 964b is formed with a threaded axial bore (not shown) for cooperating with a threaded portion 966a of an elongated articulation shaft 966. The distal end of shaft 966 is pivotably connected to a pivot pin 968 provided in the articulated knuckle 840 of the fastener applying assembly 818. In use, rotation of wheel 822 in one direction will cause the internal pinion gear 964b to rotate in an opposed direction as it is driven by the outer ring gear 964a. Consequently, the threaded portion 966a of articulation shaft 966 will be driven in a longitudinal direction to effect pivotal movements of the fastener applying assembly 818 relative to the body 816 of surgical apparatus 810. The third control mechanism activated by wheel 824 is configured to effect the independent rotation of the fastener applying assembly 818 (i.e., about the z-axis) is illustrated in Figs. 87 and 89 and includes a pinon gear assembly 974. Pinion gear assembly 974 includes an outer ring gear 974a and a pair of internal pinion gears 974b and 974c. Pinion gear 974b meshes directly with the outer ring gear 974 and pinion gear 974c meshes with pinion gear 974b. Thus, the directional component of the rotation imparted to wheel 824 by the user will be identical to that which is imparted to pinion gear 974c. A transition shaft 976 extends from pinon gear 974c, through the elongated body 816 of surgical apparatus 810, to a transmission gear set 978 which is disposed adjacent the distal end of body 816. The transmission gear set 978 serves to translate the directional component of rotation imparted to the transition shaft 976 by pinion gear 974c to a rotator shaft 980 which is disposed in coaxial relationship with the longitudinal axis of the elongated body 816. The transmission gear set 978 includes a pair of pinion gears 978a and 978b. Pinion gear 978a is connected to the distal end of transition shaft 976 and pinion gear 978b is connected to the proximal end of rotator shaft 980. The distal end portion 980a of rotator shaft 980, is configured in the form of a flexible coupling, and is fixedly mounted within the mounting portion 834 of anvil member 830 (see, for example, Figs, 72-74). An axial bore extends through the entire rotator shaft 980 to accommodate the passage of the actuation cable 860 which actuates the rotary cam 850 to approximate the cartridge housing 826 and the anvil 830. Referring to Fig. 87a, an alternative embodiment of the subject invention may also include a rotation transmission assembly 990 having a rotating adapter sleeve 992 disposed in the distal end of the elongated body 816 and mounted to the distal end portion 980a of rotator shaft 980. A pair of flexible rod members 994a and 994b, preferably formed of a shape memory alloy, extend from the adapter sleeve 992 through the articulated knuckle 840 and into the mounting portion 834 of anvil member 830 where they are fixedly secured to the anvil member 830. In use, the directional component of rotation which is imparted to rotator shaft 980 is transferred to the adapter sleeve 992, which, in turn, transfers rotation through the articulated knuckle 840 to the fastener applying assembly 818 to effect the independent rotation thereof. Referring to Figs. 90 and 90a, another surgical apparatus constructed in accordance with a preferred embodiment of the subject invention is illustrated and is designated generally by reference numeral 1010. Surgical apparatus 1010, like the surgical apparatus 810 described hereinabove, is configured to provide the surgeon with an increased range of operability during the performance of an endoscopic or laparoscopic surgical procedure. However, surgical apparatus 1010 differs from each of the instruments described previously herein, in that the handle assembly 1012 thereof has a pistol-like configuration. More particularly, the handle assembly 1012 of surgical apparatus 1010 defines a barrel portion 1014, a stationary hand grip 1016 which depends angularly from the barrel portion 1014 and an actuation handle 1018 which is pivotally associated with the stationary hand grip 1016. A trigger 1020 is slidably associated with the stationary hand grip 1016 of handle assembly 1012 and includes a unique safety mechanism 1025 which is adapted to maintain the trigger 1020 within a recessed area of the stationary hand grip 1016 to preclude user access thereto prior to effecting a proper closure sequence as will be described in greater detail hereinbelow. Referring to Fig. 91, the barrel portion 1014 of handle assembly 1012 is configured to house an elongated compression chamber 1022 within which a piston 1023 translates when the surgical apparatus 1010 is actuated (see generally Fig. 94). The angularly depending stationary hand grip 1016 of handle assembly 1012 is configured to house a pneumatic actuation assembly 1024 which includes a gas supply canister 1026, a valve 1027 which is movable into communication with the supply canister 1026, and a firing control mechanism 1028 which includes a rocker link 1030 and a cooperating latching link 1032. The pivoting actuation handle 1018 of handle assembly 1012 is configured to effectuate approximation of the cartridge assembly 1034 and the anvil member 1036. These are each operatively associated with the articulated distal end portion 1038 of surgical apparatus 1010 and which together define the fastener applying assembly 1035 illustrated in Fig. 90. Actuation handle 1018 is operatively connected to a pivot link 1040 which extends to an approximation shaft 1042 disposed within the barrel portion 1014 of handle assembly 1012. Approximation shaft 1042 extends from the handle assembly 1012, into the elongated body 1044 of surgical apparatus 1010, where it interconnects with an approximation cable (i.e. actuation cable 860 of surgical apparatus 810 which is illustrated in Figs. 71 and 72). In use, movement of the actuation handle 1018 from the position illustrated in Fig. 91 to that which is illustrated in Fig. 94 will effect the clockwise rotation of pivot link 1040 about pivot pin 1046. As a result, the approximation shaft 1042 will be drawn in a proximal direction and the cartridge assembly 1034 and anvil member 1036 of fastener applying assembly 1035 will be moved into a closed position. Referring to Figs. 92 and 93, in conjunction with Fig. 94, after the fastener applying assembly 1035 has been closed, safety mechanism 1025 may be depressed to cause the trigger 1020 to be released from and to extend from the recessed area formed within the stationary handle 1016 of handle assembly 1012. Safety mechanism 1025 includes a spring biased transverse blocking shaft 1037 having an undercut 1037a formed therein, and a planar engaging plate 1039 having an upturned end portion 1039a. Engaging plate 1039 is mounted on the trigger shaft 1020a which is biased distally by a compression spring 1049. To release the trigger 1020, the blocking shaft 1037 is moved from a first position against the bias of an internal compression spring 1037b, shown in Fig. 92, in which the upturned portion 1039a of engaging plate 1039 abuts the blocking shaft 1037, to a second position, shown in Fig. 93, in which the blocking shaft 1037 is shifted to enable the upturned portion 1039a of engaging plate 1039 to move through the undercut 1037a of blocking shaft 1037, and permit the trigger 1020 to translate into a user accessible position under the influence of compression spring 1049. With continued reference to Figs. 92 and 93, the proximal end portion of trigger shaft 1020a defines a tapered firing block 1052 which is dimensioned and configured to interact with the rocker link 1030. As described previously hereinabove with respect to the firing control mechanism 915 of surgical apparatus 810, when this apparatus is fired, the rocker link 1030 operatively interacts with the latching link 1032 to effect the controlled movement of the valve 1027 towards the stationary gas supply canister 1026. Referring to Fig. 94, depression of trigger 1020 will cause the firing block 1052 to urge the rocker link 1030 in a counter-clockwise direction about the transverse shaft 1054. As rocker link 1030 rotates, it interacts with latching link 1032, causing the rocker link 1030 to shift laterally and the latching link 1032 to rotate counter-clockwise about transverse shaft 1056 into a latching position. At such a time, the valve 1027 will be urged toward the gas canister 1026 and gas will be expelled therefrom. In one embodiment of the invention, valve 1027 is mounted in a chassis with a mounting means, e.g., a pin, introduced through the chassis to limit the travel of valve 1027 therewithin. The gas will then pass through a flexible conduit 1058, into the compression chamber 1022 where it will serve to drive the piston 1023 in a proximal direction against the bias of a return spring 1057. As the piston 1023 travels proximally, it draws therewith a drive shaft 1059 which extends into the body portion 1044 of surgical apparatus 1010 to interact with the fastener applying assembly 1035. When the piston has completed its stroke, as shown for example in Fig. 95, a stem 1060, which extends proximally from the piston 1023, will interact with an outwardly depending portion 1063 of a release shaft 1062 and will urge the release shaft 1062 in a proximal direction. Release shaft 1062 includes a depending distal portion 1064 from which extends a transverse detent 1066. Detent 1066 is dimensioned and configured to interfere with the latching link 1032 and cause the disengagement of the latching link 1032 and the rocker link 1030 after the apparatus 1010 has been actuated. Once disengaged, each of the links will return to their respective prefired positions, spaced from one another within the stationary hand grip 1016. The release shaft 1064 also interacts with an indexing counter mechanism 1068 which is similar to that which is provided in surgical apparatus 810. Referring again to Fig. 91 in conjunction with Figs. 95 and 95a, the counter mechanism 1068 of surgical apparatus 1010 includes a rack member 1070 which is slidably disposed in the barrel portion 1014 of handle assembly 1012 adjacent the compression chamber 1022 and a cantilevered latch spring 1071 which interacts with the rack member to maintain the longitudinal position thereof. The rack member 1070 includes five notched engagement areas 1070a-1070e configured to receive a ratchet tooth 1072 which depends from the release shaft 1062. Each of the engagement areas 1070a-1070e have associated therewith corresponding numerical indicia which are visible through a windowed porthole 1074 formed in the barrel portion 1014 of handle assembly 1012. In particular, the engagement areas 1070a-1070d have associated therewith the numerals "4-1", respectively. These numerals correspond to the number of times the surgical apparatus 1010 may be operated to sequentially apply fasteners to body tissue during a surgical procedure. Engagement area 1070e has associated therewith the numeral "0", which, when viewed through the windowed porthole 1074, as illustrated in Fig. 95a, indicates to the user that surgical apparatus 1010 can no longer be operated. The first four engagement areas of rack member 1070 are configured to permit the relative movement of the ratchet tooth 1072 and the rack member 1070, while the fifth engagement area 1070e is configured to inhibit the relative movement of the ratchet tooth 1072 and the rack member 1070. As a result, after the fourth operation of surgical apparatus 1010, longitudinal movement of the release shaft 1062 will be inhibited to the extent that the latching link 1032 will be released from rocker link 1030 but it will not be permitted to return to its prefired position as shown specifically in Fig. 95. Thus, further interaction between the latching link 1032 and the rocker link 1030 will not occur, and the surgical apparatus 1010 will be advantageously rendered inoperative. Referring to Fig. 96 in conjunction with Figs. 90 and 90a, the articulation control mechanism 1080 of the subject invention is illustrated. The articulation control mechanism 1080 incudes a rotation knob 1082 within which is housed a pinion gear assembly 1084 including an outer drive gear 1084a which is operatively connected to rotation knob 1082 and which rotates in response to user rotation thereof. The outer drive gear 1084a meshes with an internal pinion gear 1084b, which, in turn, is operatively connected to an articulation shaft 1085 which extends through the elongated body 1044 of surgical apparatus 1010 to the fastener applying assembly 1035. The articulation shaft 1085 operates in substantially the same manner as the articulation shaft 966 of the surgical apparatus 810 described hereinabove. The articulation shaft 966 translate in a longitudinal direction in response to the rotation of pinion gear 1084b to effect articulated movement of the fastener applying assembly 1035 about the "y-axis" illustrated in Fig. 90a. Referring to Fig. 97 in conjunction with Figs. 90 and 90a, the rotation control mechanism 1090 of surgical apparatus 1010 includes a rotation knob 1092 which is disposed substantially within the barrel portion 1014 of the handle assembly 1012. A rotation shaft 1094 extends from rotation knob 1092 to a pinion gear assembly 1096 which is housed within a rotation collar 1098. The pinion gear assembly 1096 includes a central drive gear 1096a which is connected to rotation shaft 1094, and an outer pinion gear 1096b which meshes with drive gear 1096a and which is operatively connected to an elongated transmission shaft 1102 which extends from the pinion gear assembly 1096, through the body portion 1044, to the fastener applying assembly 1035, to effect the independent rotation thereof about a longitudinal axis extending therethrough (i.e. the z-axis as shown in Fig. 90a). It is further contemplated accordng to the present invention that a braking structure may be provided adjacent rotation knob 1092. The braking structure would be axially displaced relative to the rotation knob 1092 in response to approximation of the anvil and cartridge, such that the braking structure would frictionally abut rotation knob 1092 in response to approximation of the anvil and cartridge. Thus, the fastener applying assembly would not be rotatable about the z-axis once the cartridge and anvil are approximated. Rotation collar 1098 is operatively connected to the body portion 1044 of surgical apparatus 1010 and functions to effect the axial rotation of the elongated body portion 1044 about the longitudinal axis defined thereby (i.e. the x-axis). Various sizes of the instrument are contemplated, as are various types of construction materials. Alternative internal components may also be utilized to distally transmit the rotation/articulation forces from the control mechanisms, e.g., rotation knobs 1082, 1092 and rotation collar 1098, to the distally positioned cooperating structures. For example, a series of nested tubular members may be provided that are operatively associated with respective rotation knobs/collars, such tubular members including pin and slot interconnections which allow relative axial motions between respective tubular members while ensuring conjoint rotation, as described hereinabove. The claims which follow identify embodiments of the invention additonal to those described in detail above.

Claims: A surgical apparatus (810) for driving surgical fasteners comprising: a frame portion (812); an elongate body portion (816) extending distally from said frame portion and defining a first longitudinal axis; a fastener applying assembly (818) associated with a distal end portion of said body portion, said fastener applying assembly including: a base portion (826); a cartridge assembly (828) mounted to said base portion, said cartridge assembly defining a proximal end portion and a distal end portion, and having a tissue engaging surface thereon, said cartridge assembly having a plurality of surgical fasteners contained therein; and an anvil member (830) mounted to said base portion and having a fastener forming surface thereon, said anvil member and said cartridge assembly being relatively movable between an open position wherein said fastener forming surface is spaced from said tissue engaging surface and a closed position wherein said fastener forming surface is in close co-operative alignment with said tissue engaging surface; means (850) associated with said fastener applying assembly and actuable from said frame portion for effecting the relative movement of said anvil member and said cartridge assembly between said open and closed positions; and means (890) movable through said cartridge assembly from said distal end portion thereof toward said proximal end portion thereof and actuable from said frame portion for ejecting said plurality of surgical fasteners from said cartridge assembly; wherein said means for effecting the relative movement of said anvil member and said cartridge assembly comprises a rotary cam member (850) pivotably mounted to at least one of said anvil member and said cartridge member and connected to an actuation mechanism (902) which extends through said body portion to said frame portion; and wherein said rotary cam member defines a non-linear cam slot (858) configured to co-operate wish a cam pin (856) mounted in at least one of said anvil member and said cartridge assembly; the apparatus being characterised in that: the base portion is pivotably connected (840-842) to said body portion and defines a second longitudinal axis extending therethrough. A surgical apparatus as recited in claim 1 wherein said means for ejecting surgical fasteners from said cartridge assembly comprises a camming sled (890) including a base portion (892) and a plurality of upstanding spaced apart cam plates (894) depending from said base portion. A surgical apparatus as recited in claim 2, wherein said means for sequentially ejecting surgical fasteners from said cartridge assembly further comprises a drive assembly including means (902) disposed at a distal end thereof for releasably engaging said base portion of said camming sled. A surgical apparatus as recited in claim 2 or 3, wherein said fastener applying assembly further comprises a knife member (906) configured for movement through said cartridge assembly in conjunction with said camming sled. A surgical apparatus as recited in claim 4, wherein said knife member is frangibly (910) mounted adjacent said distal end portion of said cartridge assembly and includes means (908a) for engaging said camming sled as said camming sled moves towards said proximal end portion of said cartridge assembly. A surgical apparatus as recited in any one of the preceding claims, further comprising a pneumatic actuation system (814) disposed within said frame portion and operatively connected to said means for sequentially ejecting surgical fasteners from said cartridge assembly. A surgical apparatus as recited in claim 6, wherein said pneumatic actuation system includes a container (914) of compressed gas and a compression chamber having an elliptical cross-section. A surgical apparatus as recited in claim 6 or 7, further comprising counter means (945) for indicating the number of times said pneumatic actuation system may be operated. A surgical apparatus as recited in claim 8, wherein said counter means comprises a ratchet assembly including a linear rack member (946) and a reciprocating ratchet shaft (944). A surgical apparatus as recited in claims 8 or 9, further comprising disabling means (948) operatively associated with said counter means for rendering said surgical apparatus inoperative after the performance of a predetermined number of operations. A surgical apparatus as recited in claim 10, wherein said disabling means comprises a linkage mechanism (918-920) operatively associated with said ratchet shaft and said pneumatic actuation system. A surgical apparatus as recited in any one of claims 6 to 11, further comprising means (950) for inhibiting operation of said pneumatic actuation system prior to said anvil member and said cartridge assembly being moved into said closed position. A surgical apparatus as recited in claim 12, wherein said inhibiting means comprises a spring biased blocking member (950) disposed in said frame portion for selectively interfering with an actuation trigger (916). A surgical apparatus as recited in any one of the preceding claims, further comprising means (822) for articulating said base portion between a first position substantially parallel to said first longitudinal axis and a second position disposed at an angle to said first longitudinal axis. A surgical apparatus as recited in claim 14, wherein said means for articulating said fastener applying assembly comprises a reciprocating shaft (966) extending through said body portion to said base portion and a rotatable drive mechanism (964) operatively associated with said reciprocating shaft for effecting longitudinal movement thereof. A surgical apparatus as recited in any one of the preceding claims, further comprising means (820) for rotating said fastener applying assembly about said first longitudinal axis relative to said frame portion. A surgical apparatus as recited in claim 16, wherein said means (824) for rotating said cartridge assembly and said anvil member relative to said base portion comprises a rotatable drive assembly (974) extending through said body portion to said base portion. A surgical apparatus as recited in claim 17, wherein said rotatable drive assembly (974) includes a first pinion gear set (974) disposed adjacent a proximal end portion of said body portion and a second pinion gear set (978) adjacent a distal end portion of said body portion, said first and second pinion gear sets being interconnected by an elongated transition shaft (976).

Inventors: GREEN DAVID T, HEATON LISA W, MCCLURE RICHARD C, MILLIMAN KEITH L, PALMER MICHELL J, SAVAGE ROBERT C, GREEN, DAVID T., HEATON, LISA W., MCCLURE, RICHARD C., MILLIMAN, KEITH L., PALMER, MICHELL J., SAVAGE, ROBERT C.
Applicants: UNITED STATES SURGICAL CORP, UNITED STATES SURGICAL CORPORATION
Application year: 1994
Main classification: A61B17
IPC codes: A61B17, A61B19